U.S. patent application number 12/043947 was filed with the patent office on 2008-09-04 for inverter transformer.
This patent application is currently assigned to Greatchip Technology Co., Ltd.. Invention is credited to Chun-Yi Chang, Masakazu Ushijima.
Application Number | 20080211615 12/043947 |
Document ID | / |
Family ID | 39732692 |
Filed Date | 2008-09-04 |
United States Patent
Application |
20080211615 |
Kind Code |
A1 |
Ushijima; Masakazu ; et
al. |
September 4, 2008 |
INVERTER TRANSFORMER
Abstract
An inverter transformer includes a coil unit and a transformer
core unit. The coil unit includes a bobbin formed with a
core-receiving compartment, and a plurality of windings including
two primary windings and two secondary windings wound around the
bobbin. The secondary windings are disposed adjacent to each other
and are coupled electromagnetically and respectively to the primary
windings. The transformer core unit includes an internal core part
that extends into the core-receiving compartment of the bobbin, and
an external core part that forms a magnetic circuit path with the
internal core part. The external core part includes a main segment
extending externally at one side of the bobbin and a protrusion
segment extending from the main segment toward a portion of the
bobbin that is disposed between the secondary windings.
Inventors: |
Ushijima; Masakazu;
(Nakano-ku, JP) ; Chang; Chun-Yi; (Taipei Hsien,
TW) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
Greatchip Technology Co.,
Ltd.
Taichung
TW
Yao Sheng Electronic Co., Ltd.
Taipei Hsien
TW
|
Family ID: |
39732692 |
Appl. No.: |
12/043947 |
Filed: |
March 6, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11240942 |
Sep 29, 2005 |
7365501 |
|
|
12043947 |
|
|
|
|
Current U.S.
Class: |
336/170 |
Current CPC
Class: |
H05B 41/2822 20130101;
H01J 61/56 20130101 |
Class at
Publication: |
336/170 |
International
Class: |
H01F 27/28 20060101
H01F027/28 |
Claims
1. An inverter transformer comprising: a coil unit including a
bobbin formed with a core-receiving compartment, and a plurality of
windings including two primary windings and two secondary windings
wound around said bobbin, said secondary windings being disposed
adjacent to each other and being coupled electromagnetically and
respectively to said primary windings; and a transformer core unit
including an internal core part that extends into said
core-receiving compartment of said bobbin, and an external core
part that forms a magnetic circuit path with said internal core
part, said external core part including a main segment extending
externally at one side of said bobbin and a protrusion segment
extending from said main segment toward a portion of said bobbin
that is disposed between said secondary windings.
2. The inverter transformer as claimed in claim 1, wherein said
primary windings are connected in series to each other, said
secondary windings having electromagnetic fields that oppose each
other and being adapted to be coupled electrically to a plurality
of loads.
3. The inverter transformer as claimed in claim 1, wherein said
protrusion segment of said external core part has two spaced-apart
protrusion portions that are respectively disposed proximate to
said secondary windings and that cooperate to form an air gap
therebetween.
4. The inverter transformer as claimed in claim 1, wherein said
coil unit further includes a tertiary winding coupled
electromagnetically to said primary windings.
5. An inverter transformer comprising: a plurality of coil units,
each including a bobbin formed with a core-receiving compartment,
and a plurality of windings including primary, secondary and
tertiary windings wound around said bobbin, said secondary and
tertiary windings being coupled electromagnetically to said primary
winding; and a plurality of transformer core units, each having an
internal core part that extends into said core-receiving
compartment of a respective one of said coil units; wherein said
tertiary windings of said coil units are interconnected to form a
closed circuit loop.
6. The inverter transformer as claimed in claim 5, wherein said
secondary winding is disposed between said primary and tertiary
windings.
7. An inverter transformer comprising: a plurality of coil units,
each including a bobbin formed with a core-receiving compartment,
and a plurality of windings including two primary windings and two
secondary windings wound around said bobbin, said secondary
windings being disposed adjacent to each other and being coupled
electromagnetically and respectively to said primary windings; and
a plurality of transformer core units, each including an internal
core part that extends into said core-receiving compartment of said
bobbin of a respective one of said coil units, and an external core
part that forms a magnetic circuit path with said internal core
part, said external core part including a main segment extending
externally at one side of said bobbin of the respective one of said
coil units and a protrusion segment extending from said main
segment toward a portion of said bobbin of the respective one of
said coil units that is disposed between said secondary windings;
wherein said plurality of windings of each of said coil units
further includes a tertiary winding wound around said bobbin of the
respective one of said coil units and coupled electromagnetically
to said primary windings of the respective one of said coil units,
said tertiary windings of said coil units being interconnected.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part (CIP) of U.S.
patent application Ser. No. 11/240,942, entitled "INVERTER
TRANSFORMER", filed on Sep. 29, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an inverter transformer, more
particularly to an inverter transformer adapted to drive
illumination of discharge lamps.
[0004] 2. Description of the Related Art
[0005] An inverter circuit is the main component that drives
illumination of discharge lamps. When an inverter is adapted for
driving a plurality of discharge lamps simultaneously, supply of
balanced current outputs to the discharge lamps is the key to
ensuring uniform illumination among the discharge lamps.
SUMMARY OF THE INVENTION
[0006] Therefore, the object of the present invention is to provide
an inverter transformer that is adapted to supply balanced current
outputs to discharge lamps so as to ensure uniform
illumination.
[0007] According to one aspect of the present invention, there is
provided an inverter transformer that includes a coil unit and a
transformer core unit. The coil unit includes a bobbin formed with
a core-receiving compartment, and a plurality of windings including
two primary windings and two secondary windings wound around the
bobbin. The secondary windings are disposed adjacent to each other
and are coupled electromagnetically and respectively to the primary
windings. The transformer core unit includes an internal core part
that extends into the core-receiving compartment of the bobbin, and
an external core part that forms a magnetic circuit path with the
internal core part. The external core part includes a main segment
extending externally at one side of the bobbin and a protrusion
segment extending from the main segment toward a portion of the
bobbin that is disposed between the secondary windings.
[0008] According to another aspect of the present invention, there
is provided an inverter transformer that includes a plurality of
coil units and a plurality of transformer core units. Each of the
coil units includes a bobbin formed with a core-receiving
compartment, and a plurality of windings including primary,
secondary and tertiary windings wound around the bobbin. The
secondary and tertiary windings are coupled electromagnetically to
the primary winding. Each of the transformer core units has an
internal core part that extends into the core-receiving compartment
of a respective one of the coil units. The tertiary windings of the
coil units are interconnected to form a closed circuit loop.
[0009] According to still another aspect of the present invention,
there is provided an inverter transformer that includes a plurality
of coil units and a plurality of transformer core units. Each of
the coil units includes a bobbin formed with a core-receiving
compartment, and a plurality of windings including two primary
windings and two secondary windings wound around the bobbin. The
secondary windings of each of the coil units are disposed adjacent
to each other and are coupled electromagnetically and respectively
to the primary windings of the corresponding one of the coil units.
Each of the transformer core units includes an internal core part
that extends into the core-receiving compartment of the bobbin of a
respective one of the coil units, and an external core part that
forms a magnetic circuit path with the internal core part. The
external core part includes a main segment extending externally at
one side of the bobbin of the respective one of the coil units and
a protrusion segment extending from the main segment toward a
portion of the bobbin of the respective one of the coil units that
is disposed between the secondary windings.
[0010] The plurality of windings of each of the coil units further
includes a tertiary winding wound around the bobbin of the
respective one of the coil units and coupled electromagnetically to
the primary windings of the respective one of the coil units. The
tertiary windings of the coil units are interconnected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other features and advantages of the present invention will
become apparent in the following detailed description of the
preferred embodiments with reference to the accompanying drawings,
of which:
[0012] FIG. 1 is a schematic diagram of the first preferred
embodiment of an inverter transformer according to the present
invention;
[0013] FIG. 2 is a schematic diagram of the second preferred
embodiment of an inverter transformer according to the present
invention;
[0014] FIG. 3 is schematic diagram of the third preferred
embodiment of an inverter transformer according to the present
invention;
[0015] FIG. 4 is a schematic diagram of a first configuration of
the fourth preferred embodiment of an inverter transformer
according to the present invention;
[0016] FIG. 5 is a schematic diagram of a second configuration of
the fourth preferred embodiment; and
[0017] FIG. 6 is a schematic diagram of the fifth preferred
embodiment of an inverter transformer according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Before the present invention is described in greater detail,
it should be noted that like elements are denoted by the same
reference numerals throughout the disclosure.
[0019] As shown in FIG. 1, the first preferred embodiment of an
inverter transformer 200 according to the present invention is
adapted to be coupled to a plurality of loads 90, each of which is
a discharge lamp in this embodiment. The inverter transformer 200
includes a coil unit 20 and a transformer core unit 30.
[0020] The coil unit 20 includes a bobbin 24 formed with a
core-receiving compartment 240, two primary windings 21, and two
secondary windings 22 disposed adjacent to each other and coupled
electromagnetically and respectively to the primary windings
21.
[0021] The primary windings 21 are connected in series to each
other. During operation, the secondary windings 22 have
electromagnetic fields that oppose each other. The secondary
windings 22 are adapted to be coupled electrically to the loads 90.
In this embodiment, each end of each of the secondary windings 22
is adapted to be connected electrically to a corresponding end of a
corresponding one of the loads 90. The other ends of the loads 90
are connected to each other.
[0022] The transformer core unit 30 includes an internal core part
31 that extends into the core-receiving compartment 240 of the
bobbin 24, and an external core part 32 that is disposed outside of
the core-receiving compartment 240 of the bobbin 24. The external
core part 32 forms a magnetic circuit path with the internal core
part 31. The external core part 32 includes a main segment 321
extending externally at one side of the bobbin 24, and a protrusion
segment 322 extending from the main segment 321 toward a portion of
the bobbin 24 that is disposed between the secondary windings 22.
In this embodiment, the external core part 32 is configured as an
E-shaped core, and the main segment 321 extends parallel to the
bobbin 24.
[0023] The following relation is applicable to the design of the
protrusion segment 322 extending toward the portion of the bobbin
24 that is disposed between the secondary windings 22:
magnetic path length = physical distance of flux path cross -
sectional area of core ##EQU00001##
[0024] This way, the effective magnetic path length is increased,
and cross interference between induced fluxes in the secondary
windings 22 due to mutual inductance established therebetween is
reduced, thereby achieving the object of balancing and stabilizing
currents flowing through the secondary windings 22.
[0025] As shown in FIG. 2, the second preferred embodiment of an
inverter transformer 200a according to the present invention
basically includes two of the transformers 200 of the first
preferred embodiment, i.e., the inverter transformer 200a of the
second preferred embodiment includes two of the coil units 20 and
two of the transformer core units 30 (as shown in FIG. 1). The
inverter transformer 200a is adapted to be integrated with a server
circuit 91 and a drive circuit 92 so as to form a backlight module
for a liquid crystal display. The primary windings 21 of each of
the coil units 20 are connected in series to each other and to the
drive circuit 92, while the series-connected primary windings 21 of
a first one of the coil units 20 are connected in parallel to the
series-connected primary windings 21 of a second one of the coil
units 20. The inverter transformer 200a of the second preferred
embodiment also achieves the object of balancing and stabilizing
currents flowing through the secondary windings 22.
[0026] As shown in FIG. 3, the third preferred embodiment of an
inverter transformer 200b according to the present invention
differs from the first preferred embodiment in that the protrusion
segment 322b of the external core part 32b has two spaced-apart
protrusion portions 323 that are respectively disposed proximate to
the secondary windings 22 and that cooperate to form an air gap 324
therebetween.
[0027] This way, the mutual inductance established between the
secondary windings 22 is reduced, thereby achieving the object of
balancing and stabilizing currents flowing through the secondary
windings 22.
[0028] As shown in FIG. 4 and FIG. 5, the fourth preferred
embodiment of an inverter transformer 200c according to the present
invention differs from the second preferred embodiment in that each
of the coil units 20c further includes a tertiary winding 23
coupled electromagnetically to the primary windings 21. The
tertiary windings 23 of the coil units 20c are interconnected to
form a closed circuit loop, where each of the tertiary windings 23
may be grounded at one end (as shown in FIG. 4), or may be directly
interconnected (as shown in FIG. 5).
[0029] As shown in FIG. 6, the fifth preferred embodiment of an
inverter transformer 200d according to the present invention
includes a plurality of coil units 20d, each of which includes a
bobbin 24 formed with a core-receiving compartment 240, and a
plurality of windings including a primary winding 21, a secondary
winding 22 and a tertiary winding 23 wound around the bobbin 24.
The secondary and tertiary windings 22, 23 of each of the coil
units 20d are coupled electromagnetically to the primary winding 21
of the corresponding one of the coil units 20d. In addition, the
secondary winding 22 of each of the coil units 20d is disposed
between the primary and tertiary windings 21, 23 of the
corresponding one of the coil units 20d. The tertiary windings 23
of the coil units 20d are interconnected to form a closed circuit
loop.
[0030] The inverter transformer 200d further includes a plurality
of transformer core units 30d, each of which has an internal core
part (not shown) that extends into the core-receiving compartment
240 of a respective one of the coil units 20d, and an external core
part 32d that is disposed externally of the core-receiving
compartment 240 and that forms a magnetic circuit path with the
internal core part.
[0031] In this embodiment, since each of the coil units 20d only
includes one secondary winding 22, the mutual inductance
established between the secondary windings 22 of the previous
embodiments is eliminated. In addition, by connecting the tertiary
windings 23 of the coil units 20d in series to each other, the
object of establishing balanced and stable output currents at the
secondary windings 22 is achieved.
[0032] While the present invention has been described in connection
with what are considered the most practical and preferred
embodiments, it is understood that this invention is not limited to
the disclosed embodiments but is intended to cover various
arrangements included within the spirit and scope of the broadest
interpretation so as to encompass all such modifications and
equivalent arrangements.
* * * * *